1. Field
This invention relates to high density pulp bales. In particular, it is directed to pulp bales for use in animal feeds.
2. State of the Art
Many agricultural manufacturing processes produce fibrous cellulosic pulps as a by-product. These by-product pulps constitute a useful source of fibrous material in producing secondary products, notably animal feeds. These pulps characteristically dry as a small-sized, loose, fluffy, electrostatic-prone shredded material. Shredded material must be protected from air currents, such as winds, during storage and transport. Specialized high sided tracks are required for localized transport of loose shred material. Loose shred typically has a density of about 17-25 lb/ft.sup.3.
The sugar industry mixes pulp by-product with a molasses by-product to obtain a more manageable dried pulp product. The dried molasses-coated pulp may be used as is, but it is more commonly compacted into pellets to facilitate its shipping and handling. Pellets typically have a density of about 40-42 lb/ft.sup.3. The pellets are either bagged for shipping, or shipped by specialized hopper truck. They must be protected from precipitation, and are thus not generally stored out of doors. Specialized hopper tracks are required for local transport of these materials.
Lengthy fibers, such as hay or alfalfa, are routinely packaged in bales for storage and transport. U.S. Pat. Nos. 3,991,670 and 4,098,180 disclose procedures for forming bales of cellulose materials, for example.
Compacted mixed by-product animal feeds and feed components are conventionally produced as pellets or blocks by means of a wet compaction method. Bales and compacted blocks are superior to pellets or loose feeds in terms of time, economy, and ease of handling and storage. Bales and blocks may be stored outside, unprotected, without loss due to wind or moisture and may be shipped without the use of specialized trucks.
Typical feeds and feed manufacturing methods are disclosed in U.S. Pat. Nos. 3,246,336; 2,707,151 and 4,012,535. Each of these patents relates to high molasses (or other sugar) content feeds or salt blocks, and makes use of a wet binder which is dried off after the feed formation process. The resultant pellets and blocks may be fed as manufactured, but are also commonly subjected to a crumbling step to produce a granular product useful for blended animal feeds. The term "high molasses content" generally refers to feeds with 30-80 percent molasses content, although such feeds more typically contain 50-60 percent molasses.
Compacted feeds may cause bloating in livestock. Pellets and chunks in the crumbled pellet or block material tend to swell as they pass through an animal's digestive system. Uncompacted feeds offer greater ease of digestion, but that advantage must be balanced against the expense of the special shipping, handling and storage requirements of loose feeds. It is also relatively inconvenient to ship loose feed for long distances. Specialized high sided trucks are used when moving loose feed locally.
Molasses-containing feeds offer the advantage of the minerals and nutrient content of the molasses, together with the disadvantage of the sugar content of the molasses. Certain significant markets tolerate no more than about eight percent sugar content. It is currently economically feasible to extract essentially all of the sugar content from molasses by-products. Sugar-extracted molasses is generally referred to as "concentrated separator by-product" or CSB. CSB provides the protein and trace minerals of molasses, and can be substituted for molasses as an additive to improve the handling properties of dried pulp.
In extracting sugar from a starting crop, such as sugar beets, the crop is first chopped or shredded and then pressed to remove all of the juice. The remaining pulp from this process dries into a fine-sized, lightweight flake or string, which is difficult to handle. Therefore, before drying, molasses or CSB is added back into the pulp. The dried pulp/additive mixture may contain up to 8 percent moisture. The dried pulp/additive mixture is then either shipped or stored as a loose shred, or it is formed into pellets, using a wet compaction method, prior to shipping or storing.
There is a need for more efficient and convenient packaging of fibrous pulp materials. There is further a need for an animal feed made from sugar beet by-products which avoids the disadvantages associated with currently available such feeds. Specifically, there remains a need for a sugar beet by-product animal feed containing little or no sugar which can be shipped in compacted form, stored without regard to the weather and fed in loose or shredded form.